34 



BULLETIN 1218, U. S. DEPARTMENT OF AGRICULTURE. 



The species of tabanids in Antelope Valley do not enter stables. 

 Many individuals of T. pkaenops and T. intensivus entered and re- 

 mained on the walls of a tent in Slinkard Valley, and occasionally 

 T. pkaenops would be seen on the screen of the laboratory at Topaz. 

 but there is no record of any tabanids in Antelope Valley biting a 

 host within a closed building. 



Horses in harness, especially those worked around the swamps 

 or in the hayfields, are greatly harassed by the flies. The parts of 



the body most in need of 

 protection are the head and 

 neck, where T. pkaenops 

 prefers to bite. For this is 

 used a hood of burlap or 

 light canvas with holes cut 

 for the eyes, ears, and nos- 

 trils. The cape of it ex- 

 tends over the neck to the 

 shoulders (fig. 18). Often 

 nets or burlap coverings 

 are used over the back and 

 rump, more especially for 

 protection against T '. punc- 

 tifer. 



REPELLENTS. 



Several repellents were 

 tested, but none of them 

 gave any marked protec- 

 tion. Tabanids are very 

 determined biters, and re- 

 pellents applied frequently 

 enough to give any protec- 

 tion have a harmful effect 

 on the hair and skin of the 



Fig. 18. — Horse hoods used to protect the head • i 



and Beck of the animals from horse-flies. animal. 



REPRESSIVE MEASURES. 



POISONING TABANIDS. 



While collecting tabanids on June 23, 1917, at a sheep camp in 

 Slinkard Valley, attention was drawn to the hide of a sheep killed 

 on the previous day. The pelt was hung to dry with the bloody side 

 out and many tabanids were on it. Tahanus intensivus was most 

 abundant. T. insuetus was next in abundance. 



On July 6, a fresh beef hide was hung over a fence at Topaz, 

 bloody side out, and the following solution was applied to it : 



Arsenite of soda pound \ 



Sugar pounds— 2* 



Tartaric acid teaspoonful \ 



Water gallons \\ 



The hide was exposed from 10.30 a. m. to 5 p. m. Xo dead taba- 

 nids were found, although as many as one-half dozen flies of T. 

 pkaenops were seen on it at one time. Only three or four dead flies 



